Method of manufacturing end closures for a vacuum cleaner dust bag



3,503,308 W. S. HENRY METHOD OF MANUFACTURING END CLOSURES FOR March 31, 1970 A VACUUM CLEANER DUST BAG FllQd March 28 1967 "II, A II'I'IIIIIIIIIL 1',

wuflzr gg un BY $4 H15 ATTORNEY United States Patent METHOD OF MANUFACTURING END CLOSURES FOR A VACUUM CLEANER DUST BAG William S. Henry, Stamford, Conn., assignor to Electrolux Corporation, 01d Greenwich, Conn., a corporation of Delaware Filed Mar. 28, 1967, Ser. No. 626,617 Int. Cl. B31d /00 US. Cl. 93-1 4 Claims ABSTRACT OF THE DISCLOSURE In order to pretensioning an elastic strip which overlies a pair of flaps hinged on a disc of a dust bag closure plate, the disc having the flaps is bent so that it forms a semicircle or arc, and the elastic strip is applied as the chord of the are. When the bent disc is straightened the elastic strip is elongated slightly providing a pretension therein to more positively close the flaps.

BACKGROUND OF THE INVENTION Disposable paper dust collectors for vacuum cleaners are known from US. Patents 2,483,169, 2,547,805 and 2,596,808. These collectors consist of a filter bag having a relatively stiff closure plate to which an open end of the bag is attached. The closure plate is usually composed of a pair of cardboard discs which are ultimately adhered together. One of these discs has an opening therein which is in register with a plurality of flaps formed in the other disc by die cutting. Sandwiched between the disc is an elastic member sandwiched between the discs and having a band portion overlying the flaps adjacent the part line thereof. When the suction tube of a vacuum cleaner is inserted through the cover plate and into the bag, the flaps are pushed against the elastic member as they pivot relative to the associated cover plate. When the suction tube is removed from the dust collector, the flaps are closed by the elastic member thereby sealing dirt and dust within the bag.

Methods and apparatus are known for manufacturing dust bag end closures having flaps and elastic bands or strips for closing the flaps, however the prior art is not known to contemplate pretensioning the bands or strips for optimum flap closure.

SUMMARY OF THE INVENTION The invention relates to the method of manufacturing a dust bag end plate having flaps for closing an opening in the end plate to prevent the escape of. dirt from the associated bag when it is removed from the vacuum cleaner for disposal. In particular the method according to the invention comprises bending at least the disc having the flaps which make up the end plate to form an arc and securing an elastic strip or band to the bent disc in overlying relation with the flaps as a chord of the arc. When the discs are folded and united in juxtaposition the band or strip is stretched thereby pretensioning the elastic member which imparts a more positive closing force to the flaps than an elastic strip or band which is in a relaxed condition when the flaps are closed.

A primary object of the invention therefore is to provide a method of attaching an elastic band to the end closure for a vacuum cleaner dust bag so that it is under tension at all times.

Another object of the invention is to provide an improved method of manufacturing end closure plates for vacuum cleaner dust bags in which an elastic flap closing member is in tension when the flaps are closed.

The foregoing objects and other objects and advan- 3,503,308 Patented Mar. 31, 1970 'ice tages will become apparent from the following description of the method in connection with the attached drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exploded, schematic perspective view of an end cover plate consisting of a pair of discs bent in accordance with the invention.

FIG. 2 is an end view of the cover plate of FIG. 1 showing the elastic strip in place as a chord of the arc of the bent cover plate.

FIG. 3 is a perspective view showing the disc seen in FIG. 1 as they are being folded into juxtaposition.

FIG. 4 is an exploded perspective view similar to FIG. 1 of a modification of the invention.

FIG. 5 is an end view of FIG. 4 showing the elastic strip in position as a chord of the arc of the bent cover plate.

FIG. 6 is a somewhat enlarged view showing the plate discs of FIG. 5 after having been folded and just prior to forming the end cover plate by securing the disc in juxtaposition.

FIG. 7 is a schematic sectional view of a method of attaching a rubber band or strip to a cardboard disc.

In the drawing reference numeral 10 generally identifies a dust bag closure plate consisting of a pair of cardboard discs 11 and 12 joined together by a fold line 13. The disc 11 is provided with an opening 14 which is large enough to receive a suction tube of a vacuum cleaner (not shown) as illustrated in the above cited prior art. The disc 12 is die cut to form a pair of flaps 15 integral therewith and hinged to the associated disc by a score line 16. The flaps may be dimensioned to pivot into the opening 14 or they may pivot away from the opening 14 depending on which way the discs 11 and 12 are folded and to which disc the filter bag is attached. In FIG. 1 the elastic strip 20 is attached to the lower surface of the disc 12 with the opening or slit 21 of the strip 20 coextending with the part line 18 of the flaps. Thus when the flaps are opened along the cut parting line 18 in a downwardly direction (as viewed in FIG. 1) the flaps project into the slit 21 as they pivot into opening 14 and into a filter bag (not shown) which is attached to the underside of disc 11 when it is folded under disc 12 as seen in FIG. 3 in which case the disc 11 would be juxtaposed below the disc 12 and the strip 20 would be sandwiched between the juxtaposed disc.

As shown in FIG. 2 the elastic strip 20 forms a chord of the are defined by the bent disc 12 and as noted above the bands of strip 20 on each side of slit 21 overlie the flaps. When the discs are juxtaposed and united by adhesive to form an end closure plate the disc 12 is unbent or straightened out thereby stretching the strip 20.

In FIGS. 4, 5 and 6 the disc 11' and 12 are bent into an are along an axis normal to the bend axis of the plate 10 as shown in FIG. 1 since with the part line 18' extends in a plane normal to the fold line 13 in FIGS. 4-6 whereas in FIG. l3 the parting line 18 is parallel to the fold line 13.

When the elastic strip 20 is attached to disc 12' as shown in FIG. 5 the discs 11" and 12' are folded along the line 13 as seen in FIG. 6. The discs are then flattened as indicated by the arrows and adhered together with the strip 20 sandwiched in between. As the discs 11' and 12' are flattened the strip 20 is stretched since the disc 12 is straightened before the discs are juxtapositioned and adhered together.

In the above description the strip 20 has been shown attached to the associated disc by a suitable glue or cement. In FIG. 7 the strip 20 is shown being attached to a disc 30 by means of stakes 31 which wedge the strip 3 20' into suitably dimensioned recessed 32 when the stakes are forced into the recesses. This method of attaching the strip 20 to a disc has the advantage that no curing or setting time is required as in the use of glue or adhesive and by making the stakes 31 of cardboard material the strip 20' is not pierced or torn as is the case if staples are used to secure the strip on a disc. It is noted that the elastic strip can tear when highly stressed by the flaps if a staple is driven through it in which event one or both of the flaps may not be closed.

The foregoing description of the drawing is given by way of example only and it is not intended that the appended claims be limited to all the details recited above.

What is claimed is:

1. The method of attaching an elastic strip having an elongated opening therein to an end closure for a vacuum cleaner dust bag in which said end closure includes at least one disc having a pair of pivotal flaps integral therewith, said flaps defining a cut parting line therebetween; comprising the steps of bending said disc in the longitudinal plane of said parting line, attaching said elastic strip on said bent disc as a chord of said bent disc in a relaxed state so that said elongated opening in said elastic strip overlies said parting line in said bent disc, and straightening said disc for elastically stretching said elastic strip.

2. The method according to claim 1 wherein said end closure comprises a pair of discs; the steps of bending References Cited UNITED STATES PATENTS 470,906 3/ 1892 Whitelaw.

990,154 4/ 1911 Mitchell. 2,070,674 2/1937 Muentener '55-367 X 2,382,356 8/ 1945 Walter 29-449 2,895,551 7/1959 Anderson et al. 931.3 3,052,588 9/ 1962 Anderson et al 93-1.3 3,307,873 3/1967 Blaszkowski 156160 X 3,383,030 5/1968 Downey 55-367 CHARLIE T. MOON, Primary Examiner US. Cl. X.R. 

